DE2832654A1 - DEHYDROCYCLIZATION PROCESS - Google Patents

Description

This invention relates to reforming hydrocarbons and in particular to the dehydrocyclization of non-aromatic Hydrocarbons in the presence of a catalyst Contains aluminum oxide with an alkali metal oxide and optionally chromium oxide. The invention also relates to manufacture of naphtha. from non-aromatic hydrocarbons by bringing them into contact with a catalyst which consists essentially of aluminum oxide, which promotes sodium, Contains potassium, rubidium or cesium oxide. Finally, this invention also relates to dehydrocyclization non-aromatic hydrocarbons in the presence of a catalyst such as alumina, which promotes sodium oxide or contains potassium oxide and chromium oxide.

It is known that unsaturated and saturated aliphatic hydrocarbons can be converted into aromatic hydrocarbons by dehydrocyclization. The aromatic hydrocarbons are valuable organic compounds and especially valuable as engine fuel, as they are highly resistant to knocking are. In general, the knock resistance values of aromatic hydrocarbons are considerably higher than those of aliphatic hydrocarbons, especially those aliphatic hydrocarbons with 6 or more carbon atoms in a straight chain, as found in natural gasoline and in fractions boiling in the middle and higher ranges, such as straight run gasoline and Naphtia from crude oil refining, can be found.

The object of the present invention is therefore to provide a process for converting aliphatic hydrocarbons into aromatic ones To make hydrocarbons available, which is characterized in particular by good yields and efficient and economical Feasibility.

809886/0926

V J

In the process according to the invention, non-aromatic hydrocarbons are formed with elimination of hydrogen and ring closure converted to aromatic hydrocarbons by subjecting them to dehydrocyclation conditions of temperature and pressure brought into contact with a catalyst which consists essentially of aluminum oxide, which as a promoter ein.Alkalimetalloxid and optionally contains chromium oxide.

In particular, according to the present invention, it is possible to obtain hexene-1 by contacting with a catalyst which essentially consists of aluminum oxide, which is promoted by sodium, Contains potassium, rubidium or cesium oxide, to be converted to benzene under dehydrocycling conditions. It is also possible within the scope of an embodiment of the invention, Hexene-1 or Hepten-1 by contacting with a catalyst which consists essentially of aluminum oxide, which contains sodium or potassium oxide and chromium oxide as a promoter, under dehydrocyclization conditions to convert into benzene or toluene.

The catalysts that are used in the context of the present invention are specifically for dehydrocyclization and Reforming of aliphatic hydrocarbons including acyclic and cyclic hydrocarbons suitable. to Hydrocarbons suitable as starting materials include olefinic and paraffinic hydrocarbons of 6 to about 12 carbon atoms in the molecule, of which at least 6 are carbon atoms are arranged in a straight chain. The invention preferably applies to monoolefins. Examples for suitable monoolefins which are produced by the process according to the invention Hexene, heptene, octene, decene, dodecene and mixtures of these compounds can be dehydrocyclized. Naphthenes having 6 to about 12 carbon atoms in the molecule are also suitable starting materials, with the naphthenes Have 6 or more carbon atoms in the naphtiene ring. Mixtures of hydrocarbons can be used "

809886/0928

V_ J

In addition, using the method according to the invention, mixtures of hydrocarbons which are in the gasoline range, i.e. between 38 and 218 C, simmer and which are relatively free of aromatic Hydrocarbons are to be improved in their aromatic content. In this way, Cat.cracker gasoline or other gasoline fractions for use as motor fuel by increasing their aromatic hydrocarbon content be improved.

The catalysts used according to the invention essentially consist of aluminum oxide with an internal surface area of at least 50 m / g and a suitable alkali metal oxide promoter, viz Sodium, potassium, rubidium or cesium oxide. Sodium oxide and potassium oxide are the preferred promoters, usually Alumina used as a catalyst support material and an alkali metal compound, which in subsequent calcination in

is

the oxide convertible, are mixed together to form the alumina-alkali metal oxide catalysts, as used in this invention. Suitable alkali metal compounds are for example the oxides, hydroxides, bicarbonates, carbonates and salts of weak acids, e.g. acetates and formates. Strong acid salts, e.g., halides, can also be used in the process of the invention. The sulfates lead to relatively satisfactory results with catalysts containing chromium oxide. Silica cannot take the place of the Alumina, can be used in the catalytic systems because of lower dehydrocyclization activity.

The alkali metal oxide-alumina catalysts of the present invention may optionally contain a chromium oxide as a second promoter. In general, chromium oxide is only used together with sodium oxide or potassium oxide on aluminum oxide. The metal promoter can be added as an oxide or as a compound which can be converted into an oxide on subsequent calcination. Suitable compounds are, for example, chromium trioxide, chromium acetate, chromium nitrate , sodium chromate and potassium dichromate "

The catalysts which can be used according to the invention can by dry Mixing or impregnating aluminum oxide or aluminum oxide-chromium oxide with one or more solutions of the appropriate Metal compound or compounds are made. The resulting mixture is dried, if necessary, and in Air calcined at about 371 to 650 ° C for about 1 to 20 hours. The product obtained can be ground and separated according to size and converted into pellets using conventional pelletizing processes will.

According to the invention it has been found that in those described above Dehydrocyclization beneficial results can be achieved if the promoters are within certain narrow limits the alumina can be used, these narrow limits depends on the inner surface of the alumina support material are. The concentration of the metal oxide promoters in the catalysts is thus according to the invention with respect to the internal Surface of the alumina and in relation to the specific alkali metal oxide promoter selected in percent by weight. Although these weight ratios depend on the specific surface area can be expressed in various ways, the invention shall hereinafter be expressed by the promoter concentration expressed as weight percent of support plus metal ions added. It was further found that there is a further dependence of the weight ratio of alkali metal to chromium on the alkali metal used itself. Although the metal promoters are in the form of their oxides after the catalyst is calcined, the concentration will for the definition of the invention given below as calculated as metal.

In Table A below is the concentration of the alkali metal oxide promoters on the alumina support in percent by weight of the metal as a function of the inner surface of the aluminum oxide support. Two surface areas are in this one

• "2

Table given for the aluminum oxide, namely 50 to 150 m / g

and> 150 m / g. The latter area can also be more specific by an inner surface of the alumina between 150 and

2 '■' ■ '
35Om / g. This marking the inner

'. . 809886/0926

The surface of the aluminum oxide support also applies to the following

de Table B.

Table A. Alkali metal oxide / alumina catalysts

Alumina- Na or K Rb or Cs

surface area, m / g . Wt% wt%

50-150 2-8 3-12

> 150 5-14 6-18

While the catalyst identified in Table A does not contain chromium oxide contained, the above-discussed relationship between the inner surface of the alumina support and the Promoter metal oxides indicated when chromium oxide is also present as a promoter in the catalyst. This connection is in the shown in Table B below.

Table B.

Alkali metal oxide / chromium oxide / aluminum oxide catalysts

Aluminum oxide- Na Cr Na / Cr weight ratio- K Cr K / Cr weight ratio-

surface weight% weight% nis weight% weight% nis

m2 / g in general preferred in general preferred

50-150 3-12 1.4-24 0.5-2.2 0.6-2.0 5-16 3.3-22.9 0.7- 0.8-1.3

> 150 6-18 3.3-15 1.2-1.8 1.3-1.7 8-20 5.3-28.6 0.7- 0.8-1.3

809886/0928

S / <S

■. -Xf- · ■

If, according to the invention, compositions are used within the ranges lying in the two tables given above, this results in active dehydrocyclization catalysts, which however have a relatively low hydrogenation activity under the reaction conditions used. Low hydrogenation activity is understood to mean, for example, that when using Hexen-1 or Hepten-T are the liquid products of the process, the olefinic ones Starting hydrocarbons and the corresponding paraffinic Compounds at a concentration of less than 28 percent by weight of the paraffin and especially at a concentration of only about 25 to 2 percent by weight, or even less.

The catalysts defined above are according to the invention for Dehydrocyclization and reforming of the above hydrocarbons used by the hydrocarbons to be reformed under dehydrocyclization conditions with the catalysts of the invention at temperature, pressure and throughput conditions brings into contact sufficient to remove the non-aromatic hydrocarbons present in the starting material to convert into the desired reformed product. The special conditions can vary widely depending on the used Source material and other requirements vary.

Dehydrocyclization can be carried out by _r the Äusgangsmaterial at a temperature in the range 371-593 ° C preferably 427-565 ° C and at a pressure in the range 0 to 2068 kPa, preferably 0 sends to 345 kPa over the catalyst. Lower effective pressure of the starting material can be achieved by adding diluents such as hydrogen to the reaction system. A hydrogen / hydrocarbon molar ratio of from about 0 to 5 can be used in the reaction. The hydrocarbon material can be passed through the reaction vessel at an LHSV (Liquid Hourly Volume Velocity) in the range of 0.2 to 5 volume units of hydrocarbon feedstock per volume analyzer per hour. Preferred is one

V. ._ / KJ

_ γ-

LHSV in the range 0.3 to 2.5.

The temperature to be used in the reforming process becomes largely determined by other operating conditions. Usually the temperature will be at a certain pressure and one certain LHSV is determined by the desired octane number of the product to be manufactured.

The catalyst according to the invention can be used in the dehydrocyclization of hydrocarbons as a fixed bed or in the form of a fluidized The reaction can be carried out continuously or batchwise. In both cases the product produced is broken down into its components using common methods such as fractionation, Adsorption, solvent extraction and the like, unreacted starting material can lead to the reaction stage will"

example 1

A series of catalysts have been prepared by impregnating individual samples of commercial alumina having an internal surface area of about 91 m / g and a particle size of 20 to 40 mesh (US Sieve Series) with an aqueous solution of an alkali metal compound. Each catalyst sample was dried at about 116 ° C (24O ° F) and calcined for 2 hours in air at about 482 C (900 ⁰ F). Each catalyst sample was placed in a tubular fixed bed reactor and a dehydrocyclization experiment with hexene-1 at an absolute pressure of 1 atm was carried out. The resulting product was cooled in an ice bath the liquid products are given in Table I below. The overall product composition for a typical experiment was determined by gas-liquid chromatography and the values are given in Table IA. The Celsius temperatures given are values rounded to whole numbers. The content of n-hexane in the n-HeKane / hexene-1 part of the liquid product in each experiment was

estimated by subtracting the equilibrium thermodynamic concentration of hexene-1 from the total hexene-1 plus n-hexane determined by gas-liquid chromatography (GLC). Detailed Analyzes of other similar products from experiments such as those shown in Table IA show that they are this is a satisfactory estimate.

Benzene production based on the liquid products obtained of experiments 1-7 is shown in graphic form in Figure 1.,

809886/0926

Table I.

No.

Dehydrocyclization of hexene-1 over alkali metal oxide / aluminum oxide catalysts Trial-related

3 weight% -Link
. used ~ F C. LHSV Sample, ...
Duration, hours Weight percent
Benzene · n-hexane - comment 0 - 1007 542 0.5 0.7-1.2 8.8 - control 0.5 NaOH 1O12 544 0.4 • 1.2-1.7 4.5 6th control 2.0 NaOH 1011 544 0.5 1.2-1.7 28.2 6th invention 3.9 NaOH 1009 543 0.4 1.2-1.7 49.9 6th invention 5.9 NaOH 1001 538 0.5 0.7-1.3 27.6 9 invention 7.9 NaOH 1001 538 0.5 0.9-1.6 30.4 - invention 20.0 NaOH 1003 539 0.5 O, 7-1.0 5.9 - control 4.0 LiOH 1005 541 0.6 0.7-1.0 2.4 4th control 3.5 KOH 1001 538 0.45 0.7-1.0 55.6 3 invention 6.6 KOH 1004 540 0.45 0.7-1.0 51.2 - invention 4.0 EbOH 1004 540 0.6 0.7-1.0 32.3 - invention 8.0 EbOH 1002 539 0.6 0.7-1.0 64.3 - Invention" 4.0 Na ₂ SO ₄ 1006 541 0.45 0.7-1.3 0.3 - control 4.0 NaCl 1009 543 0.6 0.7-1.0 not ge
found control

1 2 3 4 5 6 7 8 9 10 11 12 13 14

N / A

N / A

N / A

N / A

N / A

N / A

Ii

Eb

Port

N / A

N / A

(1) hexene-1 was passed over the catalysts at a Tenperatur of about 427 to 482OC (800-90O ⁰ F) for a period that is indicated by the first number in this Sjgälte .and in the field. ranged from 0.7 to 1.2 hours; only afterwards were the samples on which the measurements were made removed.

ro

co

cn cn

Tabel IA Overall product composition Experiment 5 Table I. component Weight percent hydrogen 2.5 methane 5.2 Ethane 4.5 Ethylene 2.0 propane 0.9 Propylene 2.7 Butane 0.4 Butene 7.2 Pentanes 0.7 CC monoolefins 9.6 Cg diolefins 4.4 Cyclopentene. 0.2 Isohexenes 0.7 n-hexenes 24.9 Hexadienes 3.5 n-hexane 1.5 Methylcyclopentane ' 1.0 benzene 23.1 toluene 2.4 Heptene 0.6 C _s + (mainly aromatics) 2.0

The results presented in Table I show that lithium oxide promoter on alumina is not an active catalyst results. Experiments 1 to 7, on the other hand, show that sodium oxide is used as a promoter. Aluminum oxide with an internal surface area of 91 m / g an active catalyst results when the sodium content is in the range is between about 2 percent by weight and above about 8 percent by weight but is less than 20 percent by weight. A Sodium content of 12 percent by weight represents the used Alumina is a reasonable upper limit. Runs 9 through 12 show that potassium and rubidium are on alumina catalysts active promoters for dehydrocyclization are- Compare one can see the results of experiments 4, 9 and 11, that with approximately equivalent weight ratios of alkali metal (approximately 4 percent by weight) sodium and potassium oxide are approximately equivalent Results with regard to benzene production and the low production of hexane as a by-product show that Rubiv? Eniger effective is »when the rubidium concentration is at about

809888/0918

8 percent by weight is doubled (see Experiment 12), the benzene production is doubled, while at the same promoter concentration in experiment 6 it can be seen that sodium is less effective than rubidium.

Thus it can be seen that for a given alkali metal, the best results are obtained from the atomic weight of the alkali metal selected depend. Experiments 13 and 14 show that the impregnation alkali metal compound used in alumina should not be chosen from halides and sulphates, since inactive catalysts are produced when using such salts. The curve shown in Figure 1 illustrates the Relationship between benzene production and added sodium promoter 0

Example 1 2

A number of catalysts were made by impregnating individual commercially available alumina samples with an internal surface of about 240 m / g and a particle size of 20 to 40 mesh with an aqueous sodium hydroxide solution for applying various Quantities of Sodium Produced on Each Sample »Each sample was dried, calcined, and placed in a reactor and for the dehydrocyclization of hexene-1 at one pressure of 1 at (absolute), used during a 30 minute trial. The tests were run at a hydrocarbon feed rate of about 0.5 LHSV and a reactor temperature of about 538 ° C (1000 ° F). The overall product composition of the produced Products was determined as before by GLC «The obtained Results are shown graphically in Figure 2 »

From Figure 2 it can be seen that a very good Bensol production with Catalysts is achieved, which can be obtained by applying about 5 to 14 weight percent, and preferably from about 7 to 12 weight percent Produces sodium as a promoter on aluminum oxide with an internal surface area of about 240 m / g »

. AS-

Example 3

A number of catalysts were made by impregnating individual samples of commercial alumina with various internal Surfaces with aqueous solutions of sodium hydroxide for applying various amounts of sodium to each catalyst sample manufactured. Silica (catalyst grade) was also impregnated with aqueous sodium hydroxide. The alumina and silica samples all had a particle size of 20 to 40 mesh. Each sample was dried, calcined and introduced into the reactor and used for the dehydrocyclization of hexene-1 at a pressure of 1 at (absolute) as described in Example 1, used. The reaction product coming out of the reactor was treated and examined as described in Example 1. The use of aluminum oxide samples of different surface The th promoter concentrations, the reaction conditions used and the results obtained are shown in Table II below.

809886/0926

Table II Dehydrocyclization of hexene-1 over sodium oxide catalysts

Attempt no.

(D

16

17th .

18th

Sodium, wt.%

Surface alumina m / g silica, m ² / g

Test conditions:

Temp., ⁰ F Temp., ⁰ C LHSV

Sample (duration, hours)

Benzene,% by weight η-hexane,% by weight

Remarks

(1) from Table I.

(2) not determined

3.9 91

1009 543 0.4

49.9 6

7.9

4.0

7.9

4.0

91

240

240

1001
538
0.5

1004
540
0.6

1003 539 0.6

1004
540
0.45

30.4
9

15.8
3

44.5 3

3.2
3

8.0

338

999
537
0.5

1.2-1.7 0.9-1.6 0.7-1.0 0.7-1.0 0.7-1.0 0.7-1.2

36.0
4th

19th

4.2

88

Invention Invention Control Invention Control Invention Control

1006 ι

541 0.6

0.7-1.0

not found

OO CO

ho

CD

cn

The fact that no benzene was produced in Comparative Run 19 shows that silica is no equivalent to alumina in the production of an active, alkali metal promoter Is a catalyst for the dehydrocyclization. The results of tests 4, 6 and 15-18 show that the highest Benzene production is dependent on both the sodium promoter concentration and the surface of the aluminum oxide. Trials 4 and 6 show that with an aluminum oxide having a surface area of about 91 m / g, a sodium promoter concentration of about 4 percent by weight gives good results while using a sodium promoter concentration of about 8 percent results in a less active catalyst. Experiments 15 to 18 show that when used of aluminum oxide with surface areas of about 240 and 338 m / g does not have a sodium promoter concentration of 4 percent by weight is sufficient for adequate production of benzene from hexene-1. However, if the sodium promoter concentration is increased 8 percent by weight, the result is active catalysts, as the results of experiments 16 and 18 show. From the numerical values is found that a sodium promoter concentration in excess of 8 weight percent for alumina with an internal surface area of about 338 m / g to a catalyst with higher dehydrocyclization activity than the catalyst used in Experiment 18 can lead.

example

A number of catalysts were prepared by impregnating individual samples of the 20 to 40 mesh particle size aluminas used in Example 2 with both sodium and chromium oxides. Sodium was first applied by impregnation of each alumina sample with an aqueous sodium hydroxide solution, drying the mixture at 24O ° F (116 ° C) and calcining the product at about 482 ° C (900 ⁰ F). After cooling, each

g09886 / 092B

Sodium-containing sample then impregnated with an aqueous solution of chromium nitrate or chromium trioxide, dried at 24O ° C (116 ° C) and 2 hours at 482 ° C (900 ⁰ F) calcined. Each catalyst sample was then used to dehydrocyclize hexene-1 at a pressure of 1 at (absolute) as in the previous examples. The reaction products were treated as previously described and their components were determined. The following Table III shows the promoter concentrations used on aluminum oxide samples with different surface areas, the chromium compound used, the reaction conditions used and the results obtained.

Table III

attempt
No.

Aluminum dioxide, Surface area / g

sering from Hexen-T over Natxiurobxid / Chroiipxid / ^ j test conditions CteSer- o ^temper g ^ ^ur LHSV ^^

Sodium added

g area, m / g. weight%.

Chromium added% by weight.

Chromium compound used

ratio.

stdr

Benzene ^a 'η-hexane' Bemer weight% 'weight% kungen

20th
21
22nd
23
24
25th
26th
27 28 29
30th
31
32
33
34

91 91 91 91 91 91 91

240 240 240 240 338 338 338 338

2.0 1.9 3.9 3.8 3.6 7.1

18.0 4.8 7.5 7.1

11.7 3.8 7.6 7.4

10.9

2.0

5.0

2.0

5.0

10.0

10.0

10.0

5.0

5.0

10.0

10.0

5.0

5.0

7.0

9.0

CrNO,

CrO.

CrNO ₀ 4, CrO.,

0.4

2.0

0.8

0.4

0.7

1.8

1.0

1.5

0.7

1.2

0.8

1.5

1.1

1.2

.1003 539

.1004 540

538

536

539

.1004 540

538

539

539
538

540
538

540

541
541

0.5

0.5

0.45

0.6

0.6

0.45

0.45

0.5

0.6

0.6

0.5

0.5

0.5

0.5

0.6

0.7-1.0 0.7-Τ, Ο 0.7-1.0 0.7-1 , χ 0.7-1.1 0.7-1.0 0.7-1.0 0 , 7-1.0 0.7-1.0 0.7-1.0 0.7-1.0 0.7-1.2 0.7-1.2 0.7-1.0 0, 7-1.0

86.4 91.2 50.7 75.5 88.8 71.3 19.8 89.9 66.6 89.2 69.2 89.2 51.4 82.2 55.2

82 87

26 83 16

83 18 83 16 65

53 11

: Control control invention

Il

Control invention control

Invention «^

Control cc »

Invention

control

invention

control

invention

a) Benzene content in the liquid product, collected in a water-ice-cooled trap *

b) The n-hexane content was determined as in connection with Example 1 ..

K)

OO CO. K)

CD

cn

.3ο -

The results, compiled in Table III, show that a

catalyst very active dehydrocyclization by applying both sodium and chromium oxide are obtained as promoters on alumina. To maintain such activity, while at the same time the hydrogenation activity is suppressed, relatively narrow ranges for the sodium and chromium concentrations must be as well as narrow ranges for the weight ratio of sodium to chromium are maintained, as in the above Table B is shown. The metal concentrations as well as the weight ratios for the desired catalysts is on the other hand depending on the surface of the aluminum oxides. In the case of cataly-

2 aluminum oxide carriers with a surface area of 91 m / g have, the results of experiments 20 and 21 show that the sodium content is too low (namely less than the desired 3 to 12 weight percent), although the Na / Cr weight ratios were in or near the desired range of 0.5 to 2.2. The result is a high dehydrocyclization activity (for benzene) as well as a high hydrogenation activity (conversion of the hexene-1 used in η-hexane) achieved. The results of the comparative experiment 24 are similar to those of Runs 20 and 21, although the sodium concentration of 3.6 percent by weight in the desired Range for sodium weight concentration, the Na / Cr weight ratio is below the specified minimum of 0.5. As a result, this leads to a high dehydrocyclization activity and a high hydrogenation activity of the catalyst. Of the Comparative Experiment 26 shows that there is a low hydrogenation activity and a low dehydrocyclization activity when the sodium content (18 percent by weight) above the stated value of 12 weight percent, although the Na / Cr weight ratio of 1.8 is in the desired range of 0.5 to 2.2. the Experiments 22, 23 and 25 according to the invention show that there are high dehydrocyclization activities and low hydrogenation activities when the sodium content and the Na / Cr weight ratio lie in the specified ranges.

809886/0926

When using aluminum oxide with a surface area of 240 m / g or 338 m / g, Runs 27, 29, 31 and 33 show that the sodium content is in the range from 6 to 18 percent by weight and the Na / Cr weight ratio must be in the range from 1.2 to 1.8, otherwise high dehydrocyclization activity and high hydrogenation activity result. If one works within the indicated suitable ranges, the mentioned desirable results are obtained, as shown by experiments 28, 30, 32 and 34 according to the invention.

Example 5

A number of catalysts were made by impregnating individual samples of alumina having a particle size of 20 to 40 mesh and a surface area of 91 m / g with an aqueous solution of alkali metal salt, drying each mixture at 240 ° F (116 ° C) and Calcine the product for 2 hours at 482 ° C (900 ° F). Each composition was then washed with an aqueous Solution impregnated with chfom nitrate, dried at 116 C (240 F) and calcined at 482 C (900 ° F) for 2 hours. Each catalyst sample was used to dehydrocyclize hexene-1 or heptene-1 at a pressure of 1 at (absolute), as in the previous examples described, used. The reaction products were also treated as described above and their components were determined. In the following Table IV are the alkali metal promoters, the chromium promoter concentrations, the reaction conditions and compiled the results achieved.

809886/0926

Table IV

Mbiioolefin Dahydrocyclisierung over MJcallttetalloxid / Chronpxid / Muminiunoxidkatalysatoren

Vers »Aluminum- alkali metal chromium to- alkali-used-Mrο oxide-top- added wt.% joined netall / Cr tes Ifonoflache m / g weight% weight ratio olefin

• Test conditions weight percent

Temp. Sample Ben- To- n- n-

(Duration zol luol Hex- Hep- = ^ Hrs) to tan

o _c LHSV

91
91
91
91

91
91
91
91

K 3.3 2.5 K 3.2 5.0 K 6.5 5.0 K 6.3 7.5 K 3.3 5.0 Wa 3.8 5.0 Ka 3.8 5.0 Wa ²⁾ 3.8 5.0 Well ³ * 3.8 5.0

1.3
0.6
1.3
0.8
0.7
0.8
0.8
0.8
0.8

Witches-1.

Witches-1 -

Witches-1

Witches-1

Hepten-1

Hepten-1

Witches-1

Witches-1

Witches-1

1002 539 0.54 '0.7-1.0 90.2 rib " 999 537 0.45 0.7-1.0 90.5 nb

1003 539 0.63 0.7-1.0 54.3 nb 1003 539 0.53 0.7-1.0 83.9 nb

4)

87

87

23

899 482 0.60 0 -0.3 3.3 61.2 nb

902 483 0.45 0 -0.3 2.1 58.6 nb

997 536 0.60 0.7-1.0 75.5 nb 26

1005 541 0 _f 50 0.7-1.0 53.9 nb 15

1003 539 0.50 0.7-1.0 20.6 nb 5

nb nb nb nb 82 41 nb nb nb

Contr.

Req. fp

Req.

Contr.

Req.

Req.

Req.

Contr.

to Table III

2) Wa-SO ₄ (aqueous) used to impregnate the carrier
'3} KaCl! Aqueous) is used to impregnate the carrier
41) nb means "not determined"

CO '

CD

cn

The results compiled in Table IV show for comparative experiments 35 and 36 with catalysts containing potassium and Chromium as promoters contain that high dehydrocyclization conditions result for a conversion of hexene-1 to benzene. When a potassium concentration is within that specified in the present invention Used in the range of 5 to 16 weight percent and within the K / Cr weight ratio range of 0.7 to 1.5 the results of experiments 37 and 38 according to the invention show that the catalysts both have high dehydrocyclization activity for the conversion of hexene-1 as well as having low hydrogenation activity.

In Comparative Experiment 39, Hepten-1 was passed over a catalyst with potassium and chromium promoters and in the experiment according to the invention Number 40 passed over a catalyst with sodium and chromium promoters. The potassium concentration of 3.3 percent by weight in Experiment 39 was below the specified minimum of 5 percent by weight, so that a catalyst was obtained which was also a proportionately possessed high hydrogenation activity though the K / Cr weight ratio was in the stated range of 0.7 to 1.5. The inventive Catalyst in Run 40 contained each promoter in the range specified according to the invention, and the results show that high conversion of hepten-1 to toluene was achieved while at the same time low hydrogenation of hepten-1 was observed in n-heptane. ■

A comparison of Runs 23 (repeated from Table III here) in which each catalyst had the same amount of sodium and chromium contained as a promoter, show that to achieve the best results the sodium component is applied in the form of sodium hydroxide (Experiment 23). Unlike the aluminum oxides containing only alkali metal as promoters, however, sodium sulfate can be used for production a catalyst with a lower activity (experiment 41) than that of the catalyst of experiment 23 are used, the catalyst activity nevertheless being satisfactorily high. The poor results of Run 42 indicate that sodium chloride is not a suitable substitute for sodium hydroxide as a source represents for the sodium promoter in the catalysts according to the invention. The weight percentage (fU% benzene and η-hexane are

determined in the same way as it is in footnotes.a and b of Table III is given.

09886 / OSI®

Claims (1)

26026 Germany Phillips Petroleum Company, Bartlesville, Oklahoma United States Dehydrocyclization process Claims 1. Dehydrocyclization catalyst based on alumina as Supported sodium, potassium, rubidium, or cesium oxide, characterized by the following relationship between the surface of the aluminum oxide carrier and the content of the alkali metal oxide: ΑΙ, Ο- surface Na or K Rb or Cs m ² / g wt .-% wt .-% 50 - 150 2-8 3-12 > 150 5-14 6-18 809886/0928 ORIGINAL INSPECTED Dehydrocyclization catalyst with sodium or potassium oxide and chromium oxide on an alumina support, characterized by the following relationship between the alumina surface area and the content of sodium oxide, potassium oxide and chromium oxide: Surface Na Cr Na: Cr K Cr K: Cr m / g weight% weight% weight weight% weight% weight 50-150 3-12 1.4-24 0.5-2.2 5-16 3.3-22.9 0.7-1.5 150-350 '6-18 3.3-15 1.2 -1.8 8-20 5.3-28.6 0.7-1.5 ο catalyst according to claim 2, characterized by the following Relationships; Al ₃ O ₃ surface Na; Cr K: Cr m ² / g wt. wt. 50-150 0.6-2.0 0.8-1.3 150-350 1.3-1.7 0.8-1.3 Process for the catalytic dehydrocyclization of acycli · = see hydrocarbons, characterized in that the acyclic hydrocarbon in the presence of a catalyst according to any one of claims 1 to 3 converted to a cyclic hydrocarbon under dehydrocyclization conditions will. 5. The method according to claim 4, characterized in that a mixture of non-aromatic hydrocarbons which ^{boils in the range from 38 to 328 °} C. is used as the starting material. 6. The method according to claim 4, characterized in that the Starting material contains 1-hexene or 1-heptene. 809886/0926